Single channel adapter for multiplex synchronous printers



May 26, 1942. I .1. A. SPENCER 9 SINGLE CHANNEL ADAPTER FOR MULTIPLEX SYNGHRONOUS PRINTERS Filed Fb. 1o, 1940 s Sheets-Sheet 1 INVENTOR. JA'MEJ 4. J'Pf/VCEA ATTORNEY.

May 26, 1942.

J. A. SPENCER SINGLE CHANNEL ADAPTER FOR MULTIPLEX SYNCHRONOUS PRINTERS 3 Sheets-Sheet 2 Filed Feb. 10, 1940 gunfire: 242: a a:

IIIII/IIIIIIII/IIIIIIIIIIIIIIIIIIIIIIIIIA 'IIIllIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII ATTORNEY.

y 6, 1942. J. ASPENCER 2,284,104

SINGLE CHANNEL ADAPTER FOR MULTIPLEX SYNCHRONOUS PRINTERS Filed Feb. 10, 1940 s Sheets-Sheet s IIIIIIII' 1 INVENTOR. mm; 4. JPENCEA ATTORNEY.

Patented Mayzeiaiz i 3 j James A. Spencer, Teaneck, N. J., assignor to a Radio Corporation of America, a corporation of I Delaware Application February 10, 1940, SerialNo. 318,234

'12 Qlai ns.

This invention relates to mechanism for use in radio and wire telegraph systems. In multiplex telegraphy, using equal-length code characters, a plurality of channels, each havingits own tape transmitter at the sending station and printing mechanism at the receiving station, are succese sively assigned to a radio or'wirelink for the duration of one code character.' This enables one to utilize all the time allotted to each channel for the sending of the messages, becausethe local printing operations for one channel, such as setting up the tape combinations and operating the printer, are taken care of while another channel is sending onits allottedtime.

In simplex telegraphy for equal-length code;

characters, the whole circuit time cannot be utilized for transmission of the characters of the code signals except by providing a storage means for the signals. In my co-pending-a'pplF cation, Serial No. 252,179 filed January 21, 1939,

I have disclosed sending and receiving mecha-' nism for single channel systems that permits one to utilize all the circuit time for the transmission of the, message by providing electromagnetic storing relays operating in connection with synchronous distributors. This invention is an improvement 'on the invention-of this application, in which mechanical apparatus takes the place of the-storingrelays. 1

An object of this invention is to provide mechanical locking mechanism forstoring signals to be fed to a synchronous printer.

Another object of'this invention is' to provide an adapter that stores the signal operations by cam and lever mechanism, with elimination of electromagnetic storing relays.

Another object of the invention is to provide mechanical devices for closing the contacts of the printer electromagnets'by a shait'rotating at a speed proportional to the-keying speed at the distant transmitter, with mechanical means for storing the signals while the printing functions are being performed.

Other objects will appear in the following description, reference being had to the drawings in which:

Fig. 1 is an elevation of the adapter mechanism.

Fig. 2 is a section taken along the line 2--2 of the adapter shown in Fig. 1.

Fig. 3 is a view of a transfer lever with the parts in switch closing position.

Fig. 4 is a bottom view of the switches. 4 r

Fig. 5 is a diagram showing the time of operation of the adapter mechanism.

Fig; 6 is a detail View of a selector lever and its operating cam.

' Fig. '7 is a diagrammatic illustration of the synchronous printer.

s Fig; 8 is a 'view of the battery connections for energization of the printer and associated-mechanism.

Fig. 9 is a conventional diagram of .part of the printer.

Fig. 10 is an end view of a modification, certain parts not being shown.

Fig. 11 is a side viewof the transfer levers and switches of the modification shown-in Fig.

The transmitting mechanism is not illustrated in this embodiment, as it is not claimed perse herein. The transmitter is fully shown and described in my hereinbeiore mentioned applica-' tion and it will be sufiicient merely to say that the transmitter sends out positive and negative pulses in proper time relation to'form the desired code characters. The specific code employed is a seven unit equal-length code analogous to the five unit Baudot code, though the invention could be used with other codesif desired, and of course interruptions of currentmay be used instead of positive and negative current pulses.

The pulses formed at the transmitter are sentout over the radio or wire link, as the case may be, and are received at the receiving station. If

the signals are sent out over a radio ilink, they are received, amplified, detected and further amplified and transmitted to the printing mechanism to line L (Fi 1) connected to the'line or signal magnet I, the other endof the magnet coil being connected to ground G-. Ii sent out over awire link the transmission line is connected to line L, as WGH'kIlOWIl. d

The adapter mechanism shown in Fig. 1 has a shaft 2 rotated at a speed in synchronism with or proportional to that of the distributor at the transmitter. The means for producing the synchronization or proportional speed of the shaft 2' may be any of the Well-known means found in.

around the shaft so that an end View of the cam assembly as seen in Fig. 2 in dotted lines has somewhat the appearance of a seven pointed star. Each of the seven cams has a cam follower on selector lever 6 pivoted at I. The cam follower of the selector lever is held against its cam by a spring 8. Each of the seven selector levers,

all being identical, has a swivel connection at the end 9 with a sword III having two projections I I, I2 which are adapted to engage the'prongs I3, I4 ofrocker arm. I5 of an armature pivoted at I6 and positioned to .be attracted by signal magnet I when it is energized. By referring to Fig. 1

it will be seen'that the rocker arm I5 extends to one side so that the prongs I3, I4 surround all seven selector levers and other parts to be referred to later. v V Each sword I0 is adapted, when lowered bythe cam action, to engage either 'arm I6 or arm II of the T-latch I8, depending upon its position. The latch I8 engages switch'lever' I9 pivoted at 1 locking cam 31. The locking cam is so adjusted inposition on the shaft 2 that the magnet rocker farm I5-'is locked against movement while the and having switch contacts 2II, 2II I, 2IIII,

2IIV, 2IV, 2IVI, or 2IVII, one contact of which is connected to a source of supply as at 22 and the other of which is connected to a wire 23I, 23II, 23]1I,23IV, 23V, 23VI, or 23VII, as the case may be, that extends to selector magnets shown in Fig. 7. There are seven swords, seven switch levers and seven selector magnets, so that each cam 4 controls the energization of a selector,

magnet.

On shaft 2 of the adapter is located a transfer cam 24 at the right of the code cams rvn as shown in Fig. 1 and a second transfer cam 25 shown at theleft of the code cams in this figure. These with their associated parts are the storing means for the signals. The two transfer cams are of the same shape, cam 25 being shown in Fig. 3. The transfer cams are spaced from the othercams by washers such as 5 and are adjusted in position for timed operation as indicated in Fig. 5. The transfer cams 24, 25 have cam followers consisting of transfer bell-crank levers 26, 21 of the samegeneral shape as the selector levers 6. Springs 28 hold the transfer levers against the cam. The ends of the transfer levers 26, 21 have pivot connections with transfer links 29 and 30 respectively. These transfer links have a suitable sliding connection with a guide and stoprod 3I. Transfer link 29 has a projection 32 extending under switch levers I9 associated with cams V, VI and VII, and transfer link 30 has a projection 33 extending under the switch levers I9 for cams I, II, III and IV (Figsl l and 4).

. When the cam follower on either of the trans the transfer link be in the down position as in Fig. 3. The transfer levers also return any closed switches to open position when their associated cam followers ride out of the cam notches.

To prevent the magnet armature or rocker arm I5 from chattering or moving from its proper position, a locking lever or latch 34 is provided. This latch engages notches in the rocker arm at- 35 to hold it either in the attracted or unattracted position.. The latch 34 is pivoted on the rod I and has a cam follower 36engaging the locking cam 31 by action of spring 38. The locking cam 3'I.is shown in Fig. 1, but its relation to the locl inglever'a'nd the rocker armI5 isbest illusselection levers 'I-VII are riding over their respective" cam projections, so that the rocker arm is held rigid while a projection on the sword I0 engages a prong I3 or I4, as the case may be, due

' to the elevationof the sword by movement of the selector lever over one of the cam projections, as will be referred to more in detail in describing theoperation of the adapter.

Inthe modification of-Fig. 10;the mechanism is in general the same as already-described, except that the projections or 40 of the transfer levers have arms 4|, 42 directly engaging projections 43; 44 on the switch arms I9, projection 44 being associated with the parts connected to cams I, II, III andIV, and projection 43 with those associated with cams V, VI and VII. 30'

The operation of the adapter will now be described in connection with the synchronous printer diagrammatically illustrated in Figs. '2 and 8, which need no detail description.

As shown in-my above-mentioned application, positive and negative pulses are sent out to constitute the codecharacter in-cable code, and these at the radio receiverare converted into current and no-current indications, but of course the original signal could have been transmitted in currentand no-current indications at the transmitter'in accordance with the American codepractice-if desired.

, Assuming-the .use ofthe seven unit code of my above-mentionedapplication and that the letter A is being transmitted, there will be a pulse for the first,-thirdand fourth code characters and no pulses forthe second, fifth, sixth and seventh code characters. Since the adapter shaft 2 is 7. being rotated insynchronism with the distributor at the transmitter or at a speed proportional thereto, the signal magnet I will be energized by the first pulse whencam I lifts its associated cam lever 6.by means of the cam projection 4 (Figs. 2 and 6). The armature extension or rocker arm I5 will then be inthe position-shown in Fig. 2. As the sword I0 is raised, projection I2 will engage prong I4 on the rocker arm. This will swing the sword over into position above arm I! of T-latch I8. As soon ascam projection passes the cam follower, the spring 8 causes the selector lever to move the sword I II against arm I I. Latch I8 willibe movedaway from the switch lever I9 associated therewith. This particular switch lever. III will not move its contactarm into engagement with its contact 2II (Fig. 4) because transfer link 30 is in the elevated position shown in Fig. 2, since thetransfer lever is at thistime riding on' the circular periphery of cam 25, as

willbe clearfrom an inspection of the timing diagram of Fig. 5. The switch. lever, however, is unlatched and thecharacter is thus stored for later use. r 7

When .cam -II. engages "its cam follower in the time allotted tolthesecond'unit, no pulse is received for the letter A. Signal magnet-I is not energized and extension I is in its left hand position (not shown in the drawings). As the cam follower rides up cam II the sword is raised by the selector lever and arm H engages projection l3 on the extension Hi. The sword point is thus moved to the right above arm I6 in latch I8. This position of the sword point for no-current characters is the one shown in Fig. 2. In this figure the signal magnet is energized but the selector is not shown in its raised position, which would have swung the sword point over into the other position. It will be clear that as the sword lowers when the selector lever cam follower rides down the projection of cam II, the latch l8 will not be moved to release the switch lever.

When the position for the third unit is reached, signal magnet I will be energized and cam III will operateits selector lever, sword and latch. Upon reaching the fourth position of the sevencharacter code, cam IV will operate its T-latch and release its switch lever. However, at this time the contacts ZII, 21111 and ZIIV will not close because they are held open by the projection 33 on the transfer link 38. Since the'letter 1 energizes the first, thirdjand fourth selector magnets (counting from the right in Fig. 6).

The first magnet attracts its armature 46 and catch 41 snaps over the end of the armature and holds it in the notch 48 of the selector bar 49. The armature and latch for only one selector magnet are shown, but all of the selector magnets have similar armatures and latches. The energization of magnets 2311 and 23111 likewise projected their armature ends into notches in their selector bars where they are held by their latches.

Switches ZIV, ZIVI and ZlVII do not close when their cams V, VI and VII operate the selector levers (Figs. 2 and 4) because no current pulses are received to energize magnet I. Nothing further happens at the printer of Fig. 7 for the time allotted to the fifth, sixth and seventh characters, but it should be noted that switch levers IQ for the cams I, II (III also, if it has been previously operated) and IV were placed in position for the unit of the next succeeding letter shortly after the position was reached for the sixth signal character (see diagram of Fig. 5). Therefore, before the first described revolution of shaft 2 is completed, additional signal units can be received and stored in the first four positions of the succeeding revolution of the shaft since the selector switch levers I9 were returned to their initial position when the transfer levers were raised by their cams leaving the cam notches.

When the second position of the succeeding revolution is reached, contact 58 connects brushes 5! and 52 (Figs. 1 and 5) and places potential on line 53 (Figs. 1 and 7). This energizes relay The armature 58 is attracted and plunger 59 moves carriage 60 to the left in Fig. '7.

Since the seven selector magnets and their respective armatures are mounted on carriage 60, the selector bars 49, 6| and 62 are moved with the carriage because the projecting ends of the armatures of those selector magnets engage the edges of notches in the selector bars. The remaining selector bars are not moved with the carriage. Shortly before the motion to the left is completed, trip 63 engages latch 41 and permits the armatures (one only being shown) to spring back into place. The armatures are freed from friction against the ends of notches 48 etc. at this time by leaf spring 64 entering notches 65 in the three selector bars, which snaps the selector bars slightly to the left. Selector magnets 231, 23111 and 23IV then resume their 'normal condition. When the three selector bars 1 reach their extreme left-hand position notches 66 in the three selector bars corresponding to the letter A are in alignment. Pull bar 61 shown more in'detail in Fig. 9 is then in position to drop into these aligned notches, but it'is held from this movement by the printing bail 68 engaging hump 69 on the pull bar.

When the carriage reaches its extreme movement to the left it opens switch contacts 10 and breaks the continuity of the holding circuit of relay 58. Thisde-energizes the relay and opens the contacts 56, which in turn de-energizes carriage operating magnet 51. The carriage return werenot returned to the right atthat time.

As the return lever 13 snapped into the notch of latch 15, printing contacts 16 closed and printing relay 17 was energized. This closed contacts I 78 andenergized'printing solenoid I9. This solenoid pulls the armature 88 downwards withits extension 8| which is pivoted to printing bail 68, the bail being pivoted at an intermediate point 82. This moves the bail upwards (Fig. 9) and permits the pull bar 61 forthe letter A to drop into the aligned notches 66 etc. in the operated selector bars. As it does this, the upwardly moving projection 82 engages the hump 69 in the pull bar and moves it upwards with the bail. This throws the type bar 83 downwards and strikes the type-pallet against the ribbon on platen 84. This prints the letter A.

Just at the time that the armature 88 of the printing solenoid completed its movement, projection 84 engaged the latch 15 and permitted the return 13 to: return the three operated selector bars to the right, whereupon leaf spring 64 snapped into groove 85 which holds these three, bars together with the others in their initial position. At about this time projection 86 opens switch contacts 81 and deenergizes the printing relay and the printing solenoid magnet. The plunger is then returned to its initial position by spring 88 (Fig 9). This returns the pull bar and brings the printing bail 68 against the hump 68 of the pull bar and moves it outwards clear of the selector bars.

The selected letter A has thus been printed and all mechanism of the printer has returned to the original position at-about the time cam -enth code units are used in a signal their cams,

swords and T-latches ;will operate in a similar previous revolution was com- 7 way atthe proper time shown in Fig. 5. The

switches 21V, 2W1 and ZI VII, however, will not close until the transfer lever 29'engages the cam depression 89 (Fig. 5) 1 in cam 24. This takes place just before cam II operates its selector lever in the revolution succeeding the one described for the signals of letter'A. The transfer lever 29;moves out upon the circular part of itscarn shortly thereafter and switches 23V, 2 3VI and [23 m (if operated) are moved back into, engagement with their T-latches l8. Hence the parts are in-normal position for receiving the fifth, sixth and seventh code, units at about the time'the position for the third unit is reached inthe adapter. e

In the Way described, the signals are stored and the, printer operated without taking circuit time away from the parts responding to the code character pulses orindications. The sys-- tem disclosedis thereforewell adapted-to single channel systems, though of course it can be used in multiple channel systems equally as well.

In the modificationshown in Fig. 10 the: op- I eration will be the same as already described.

The only difie rence isthat the's'witches I 9fare held in storage position'by the end of thetrans; fer levers instead of bylinks pivoted thereto.

Having describedmy invention, what I claim 1s: 7 I 1 r V 1. In an electrical printing telegraph system for multi-unit equal iengthcode characters, a printerhavinga selector magnetfor each code unit, a rotatable adapter shaftga switchin the circuit of the coil of'eachrnagnet, a latch normally holding each switchopen, means operated by said shaft for releasing the "latches'successively atuniforrn time intervals in, a continuous cycle, supports; normally hol ing said switches open,- and additional means operated by said shaft for releasing said supports.

and means; for releasing said supports.

to closing and opening positions, means operatedby the signal magnet for directing said plungers to one oi said positions on receipt of a signal and to,-the;other position on absence of a signal, supports normally holding said switches open,

4. In an electrical printing telegraph system for;multiunit equa1 length code characters, a printer having a selector magnetfor each code unit,a switch in the circuit of the coil of each magnet,- a latch normally holding-each switch open, means for releasing the latch es at uniiorni time intervals in, continuous cycles a support normally holding part oi said switches open, an additional support, normally holding the re-' maining switches open, and means for releasing said supports in timed succession.

5. Ina'n electrical printingtelegraph system for multi-unit equal length code characters, a printer having a selector magnet for each code unit, a rotatable adapter shaft having cams uniformlyspaced therearound, there being one cam for each code unit, a switch in the circuit of the coil of each magnet,,a latch normally holding eachswitch open, means operated by said cams for leasing the latches, a support normally holding part of said switches open, an additional supportnorrnallyflholding the remaining switches-open and additional cams on said shaft having means for'. releasingsaid supports in timed succession. u

6. In an'electrical printing telegraph system for 'rnulti-unit equal length code characters, a printer having a selector magnet for each code 11mm rotatable adapter shaft having cams uni-.

formly spaced therear'ound, th'ere'being one cam for each code u'nit,ja switch in the, circuit of the coil of each .ma'g'nema latch' normally holding each switch open, plungers operated by said cams for moving the latches to closing and opening positions, means operated by the signal magnet for directing saidplun'gers 'to one of said positions on receipt of a signal and to the other position on absence of 'asignal, supports normally holding part of said switches open, an additional supportnormally holding the remaining switches'open, and additional cams on said shaft havingmeans for releasing said supports in timed succession.

.7. In', anjelectrical printing telegraph system for multi-unit' equal length code characters, a

. printer. having a selector magnet forfe'ach code 2.-In an electrical printing telegraph system for multi-unit equal length code characters, a-

' printer having a selector'magnet for each code unit, a rot atable adaptershaft having cams uniformly spaced therearound, there being one cam for each code unit, a switch in the circuit of the coil of each magnet," a latch normally holding each switch open, means operatedby said cams;

for releasing the latches,- supports normally one cam for each code unit, a switch in the cirholding said switches open, and additional cams on saidshaft ha'ving' means for releasing said supports.

printer having 'a selector magnet for each code unit, a signal magnet for receiving the incoming signals, a rotatable adapter shaft having cams uniformly spaced therearound there being one cam for each code unit, a switch in the circult of the coil of .each selector magnet, a latch normallyholding -each 'switch open, i plungers operated? by nw'cams for moving the la tche s 3. In an electrical printing telegraph system for multi-unit equal length code characters, a

unit, a semi-magnet for receiving'the incoming signal, airota'table -adapter shaft 'havingcams uniformly. spaced therearound, there being cult of the coil of each magnet, a latch normally holding each switchv open, p'lungers operated by said cams for moving the latches to'closing and opening positions, means operated by the signal magnet for directing said plungers tolone of said positions on receipt of a signal. and to the other position on. absence of aisignal, a support hermallyholding partof-said? switches open, an additional support normally holding the remaining' switches open and additional cams on said'sliaft having means for releasing said supports in timed succession;

[8. In an electrical printing telegraph system for inulti'unitequal lengthcode characters, a

5 printer liaving 'a SelectOr rnagnet for each code,

unit,I a rotatable adapter"shait having cams, a switch in the circuit ofthe coil of each magnet,

a latch normally holding each switch'open, there 1 being Va can a switch and alatch associated to-.

gether for each code unit, means operated by each cam for releasing its latch at a predetermined point in each revolution of the shaft, 21

support normally holding open the switches associated with the latches released in the fore part of each revolution, an additional support normally hclding open the switches associated with the remaining latches, a cam on said shaft for releasing the first-mentioned support after the last latch associated therewith has been released in that revolution, and a cam on said shaft for releasing the second-mentioned support after the last latch associated therewith has been released and before the first latch associated therewith has been released in the next revolution of the shaft. V

9. In an electrical printing telegraph system for multi-unit equallength code characters, a printer having a selector magnet for each code unit, a rotatable adapter shaft having cams, a

switch in the circuit of the coil of each magnet, a latch normally holding each switch open, there being a cam, a switch and a latch associated together for each code unit, a plunger operated by each cam for moving its latch to closing and opening positions at a predetermined point in each revolution of the shaft, means operated by the signal magnet for directing said plungers to one position on receipt of a signal and to the other position on absence of a signal, a support normally holding open the switches associated with the latches released in the fore part of each revolution, an additional support normally holding open the switches associated with the remaining latches, a cam on saidshaft for releasing the first-mentioned support after the last latch associated therewith has been released in that revolution, and a cam on said shaft for releasing the second-mentioned support after the last latch associated therewith has been released and before the first latch associated therewith has been released in the next revolution of the shaft.

10. In an electrical printing telegraph system for multi-unit equal length code characters, a printer having a selector magnet for each code unit, a signal magnet for receiving the incoming signal, a rotatable adapter shaft having cams,'a switch in the circuit of the coil of each magnet, a latch normally holding each switch open, there being a cam, a switch and a latch associated together for each code unit, a plunger operated by each cam for moving its latch to closing and opening positions at a predetermined point in each revolution of the shaft, means operated by said signal magnet for directing said plungers to one of said positions on receipt of a signal and to another position on absence of a signal, a support normally holding open the switches associated with the latches releasedin the fore part of each revolution, an additional support normally holding open the switches associated with the remaining latches, a cam on said shaft for releasing the first-mentioned support after the last latch associated therewith has been released in that revolution, and a cam on said shaft for releasing the second-mentioned support after the last latch associated therewith has been released and before the first latch associated therewith has been released in the next revolution of the shaft.

11. ,In an electrical printing telegraph system for multi-unit equal length code characters, a I

printer having a selector magnet for each code unit, a signal magnet for receiving the incoming opening positions. at a predetermined point in" each revolution of the shaft, means operated for the signal magnet fordirecting said plungers to one of said positions'on receipt of a signal and tothe other position on absence of a signal, a support normally holding open the switches associated with the latches released in the fore part of each revolution, an additional support normally holding open the switches associated with the remaining latches, a cam on said shaft for releasing the first-mentioned support after the last latch associated therewith has been released in that revolution, and a cam on said shaft for releasing the second-mentioned support after the last latch associated therewith has been released and before the first latch associated therewith has been released in the next revolution of the shaft. v

12. In an electrical printing telegraphsystem for multi-unit equal-length code characters, a printer having a selector magnet for each code unit, a signal magnet energized and de-energized by the signals, a switch having one position for switches in said position and means for moving said additional means away from switch-holding position independently of the energization of said signal magnet.

'JAMES A. 'srENcER. 

